Electrically operable drive arrangement for venetian blinds

ABSTRACT

The invention relates to an electrically operable drive arrangement for venetian blinds with at least one draw tape which tape is wound up or down by a motor located in the header. Switches in the header are operated by a feeler which moves respectively perpendicular to or parallel to the tape as the tape moves from its normal tangential position on the take-up roller upon bottoming of the blind, or when the blind reaches fully raised position.

United States Patent Horst et al. Sept. 17, 1974 ELECTRICALLY OPERABLE DRIVE [56] References Cited ARRANGEMENT FOR VENETIAN BLINDS UNITED STATES PATENTS Inventors: Wilfried Horst, bu g; He 3,603,372 9/1971 Dietzsch 160/168 Coldewey, Jeddeloh; Mario Ammazzalorso, Wardenburg; Primary ExaminerPeter M. Caun Schuppler, Oldenburg of Attorney, Agent, or F irm-Olson, Trexler, Wolters, Germany Bushnell & Fosse, Ltd.

[73] Assignee: Firma Justin Huppe, Oldenburg,

Germany [57] ABSTRACT [22] Filed: Dec. 4, 1972 The invention relates to an electrically operable drive arrangement for venetian blinds with at least one draw [21] Appl 3ll762 I tape which tape is wound up or down by a motor located in the header. Switches in the header are oper- [30] Foreign Application Priority Data ated by a feeler which moves respectively perpendicu- Jan. 13, 1972 Germany 7201069[U] lar to of Parallel to the tape as the tape moves from its normal tangential position on the take-up roller upon [52] US. Cl. 160/168 bottoming of the blind, or when the blind reaches fully 51 1m. (:1 E06b 9/30 raised Position- [58] Field of Search 160/168 7 Claims, 6 Drawing Figures PAIENIEDSEPI H914 3' 83 SHEET 101 2 5,911

PATENTED SEP 1 71914 SBEEI 2 8? 2 ELECTR ICALLY OPERABLE DRIVE ARRANGEMENT FOR VENETIAN BLINDS Electrically Operable ,drive arrangements for venetian blinds have been widely usedin recent years. In spite of this wide use, however, the limit switch arrangements necessary to stop such blinds at fully raised and fully lowered positions have not yet reached a satisfactory state of development. All known constructions are relatively expensive with time consuming installation. Since these arrangements are also predominantly quite prone to trouble, high repair costs are incurred in connection with time consuming repair work.

The invention is based on the problem to place a drive arrangement of the aforementioned type, avoiding the mentioned disadvantages, in a sturdy, simple manner,safe in operation, in the header of a venetian blind in such a way that the blind can assume an upper and lower adjustable end position reliably and reproduceably.

In accordance with the invention, the problem is solved by the fact that a feeler is arranged movable in a first plane perpendicular to the draw tape to operate one switch and also in a second plane which runs essentially parallel to the loaded draw tape to operate a second switch for the motor.

This solution has the advantage that the draw tape is felt by a single feeler and that each of the feelers two planes of movement pertains to a limit position of the bottom board of the blind and the feeler, in each of its two planes of movement, actuates one of the two switches.

These two switches can advantageously be made as microswitches. The upper limit position can be adjusted especially advantageously to a certain height factor, for instance, agreeing with adjacent similar venetian blinds, if a moving element is attached on the bottom board, for instance in the form of an adjustable release pin.

Advantageous guiding of the feeler in relation to the draw tape is obtained if the end of the feeler is provided with a slottedpassage opening which encloses the draw tape on all sides. Among other things, this has the advantage that, if necessary, the draw tape can be easily unthreaded and threaded.

Further details and advantages of the invention can be learned from the following description of a preferred type example with reference to a drawing, wherein: I

FIG. 1 is a schematic, perspective and partly sectional view of a drive arrangement, in accordancewith the invention, for a venetian blind which, for reasons of clarity, has only a single draw tape with pertaining feeler;

FIG. 2 is a cross section through the header of the venetian blind of FIG. 1 with tightened draw tape;

FIG. 3 isthe same view as in FIG. 2, however, with relieved draw tape;

FIG. 4 is a longitudinal section through the header of FIGS. 2 and 3 with a switch for the upper limit position switch-off of the motor and with the feeler in rest position in relation to this switch; I

FIG. 5 is a cross section through the header corresponding to FIGS. 2 and 3, however, with the feeler moved into its upper switch-off position by the stack of slats; and

FIG. 6 is a view from above on the header, which is open on top, witha switch for the lower limit position switch-off of the motor and with a limit position switching setting of the feeler, indicated by dash-dots, for the lower end position of the bottom board with the draw tape released. I

In FIG. 1, an electrically operable drive arrangement for venetian blinds is schematically illustrated. For reasons of clarity this venetian blind is illustrated with only one draw tape 2 and with only three slats 4; as usual with such blinds, a larger number of slats 4 is guided on the draw tapes 2 by means of openings.

The upper part of the venetian blind shown in the drawing consists of a hollow header 1 which is open at the top and which is fastened in the usual manner on the ceiling or on a wall and in which there is located a motor 5 as a drive source of the blind, and a horizontally running drive shaft 6 on which, among other things, a winding roller 7 is placed. The motor 5 can be operated in both directions of rotation so that the draw tape 2 guided on the winding roller 3 can be wound or unwound according to the direction of rotation.

In the example illustrated in the drawing, all elements for turning of slats 4 and for the switch-off of the motor 5 in both turning directions are put together in a turning and switch-off arrangement whose base plate 10 is mounted in the header 1 by means of screws (not shown) so that it can be exchanged. The base plate 10 has several openings of which opening lla serves as a passage for a feeler 12, which will be described in detail later, and an opening 11b which serves as a passage for the draw tape 2. Additional openings are provided for straps (not shown in the drawing) for the adjustment of slats 4.

As can be seen, especially in FIGS. 4 and 6, the feeler 12 has a point of rotation 13 in the form of a screw threaded in the base plate 10; however, since the free end of the feeler 12 is bent at an angle toward the bottom and is guided through the opening 11a of the base plate 10, the feeler 12 can be turned in the horizontal plane at an angle limited by the length of the opening 1 la.

This horizontal turning plane is designated as the first plane of movement of the feeler 12. According to FIG. 6, the feeler 12 is shown in connection with the tripping of a first microswitch 16 which, in the present example, is designated as a work contact and is located in the circuit of the motor 5 and therefore closed when the feeler 12 is in its operating position indicated by dashdotted lines. The feeler constantly assumes this operating position as long as the bottom board 3 hangs on the draw tape and stretches it tangentially from the roller 7 according to FIG. 1.

During the lowering of the venetian blind, as soon as the bottom board reaches the end position and simultaneously the draw tape 2 fastened on the winding roller 7 releases the feeler 12, the feeler is pressed in the direction of the arrow (FIG. 3) by the spring-loaded tripping of the microswitch whereby the motor is switched off in the downward direction. The switching-off in the downward direction is analogously effected in the same manner by the release of the draw tape 2 when the bottom board encounters an obstacle and the tape 2 slackens.

As FIG. 6 shows, the feeler 12 has a second release attachment 15, which pertains to a microswitch 17, with a vertical plane of operation. On the basis of its relatively great length between the point of rotation 13 and guide slot 18, the feeler 12 is in a position to follow, with its free end, a vertically running second plane of movement when an element provided in connection with the bottom board 3 bears (in the upper end position of the venetian blind) on this free end of the feeler from below. According to FIG. 5, this element is the uppermost slat 4 of the slat package which is pushed together, This slat 4 presses against the bent-over free end of the feeler 12. If, according to FIG. 5, the feeler is moved vertically upward toward the base plate 10, the second release attachment trips the second microswitch 17, which is made as a rest contact, and the motor 5 is switched off in its upward direction of rotation.

As a variation from the switch-off action in the upper end position of the venetian blind described before, the actuation of the free end of the feeler 12 according to FIG. 1 is not carried out by the uppermost slat 4 but by a separate adjustable release pin 21 which is attached on the bottom board 3 and protrudes through the opening for the draw tape in the slats adjacent to the draw tape 2 when, during the upward movement, the slats 4 are stacked on the bottom board 3 one after the other. By means of this adjustable release pin 21 there can be achieved a uniform upper limit position arrangement of all bottom boards 3 of quite a number of blinds which, for instance, are installed in a common window front independent of the installing tolerances which the individual headers 1 of the various blinds have with respect to each other.

As mentioned before, the draw tape 2 is guided through the guide slot 18 on the free end of the feeler 12. This guide slot 18 has a widening in the form of a threading slot 19 which permits the threading and unthreading of the draw tape 2. This is especially valuable during servicing or repair work when the feeler 12 must be separated from the draw tape 2. In this case, the slats 4 and the bottom board 3 need not be separated from the draw tape.

The invention is claimed as follows:

1. An electrically operable drive arrangement for venetian blinds with-at'least one draw tape comprising a windup roller and motor located in a header, a bottom board on a blind attached to said draw tape, switch operating means including a single unitary feeler mounted to said header and movable in a first plane running essentially transversely to the loaded draw tape with the feeler end portion operatively adjacent and responsive to the transverse location of the tape for effecting movement of the feeler in said first plane and additionally movable in a second plane which runs essentially parallel to the loaded draw tape with the said feeler end portion responsive to vertical location of the blind bottom board for effecting movement of the feeler in said second plane, a first switch operable by said feeler upon movement thereof in the first plane perpendicular to said draw tape, and a second switch operable by said feeler in the second plane parallel to said draw tape, each of said switches being effective to stop operation of said motor in a given direction of rotation.

2. Arrangement according to claim 1 wherein the feeler is movable in one plane of movement by means of an element coupled with the bottom board.

3. Arrangement according to claim 2 wherein the moving element is an adjustable release pin.

4. Arrangment according to claim 1 wherein both switches and at least a part of said feeler are substantially located within the header but with the end portion of the feeler disposed exteriorly of the header.

5. An arrangement as claimed in claim 4 wherein the exteriorly disposed feeler end portion is offset from the body thereof and disposed in the path of vertical movement of the blind.

6. Arrangement according to claim 1 wherein the feeler has a slotted passage opening which encloses the draw tape substantially on all sides.

7. Arrangement according to at least claim 1 wherein the feeler and both switches are mounted on a base plate installed in the header. 

1. An electrically operable drive arrangement for venetian blinds with at least one draw tape comprising a windup roller and motor located in a header, a bottom board on a blind attached to said draw tape, switch operating means including a single unitary feeler mounted to said header and movable in a first plane running essentially transversely to the loaded draw tape with the feeler end portion operatively adjacent and responsive to the transverse location of the tape for effecting movement of the feeler in said first plane and additionally movable in a second plane which runs essentially parallel to the loaded draw tape with the said feeler end portion responsive to vertical location of the blind bottom board for effecting movement of the feeler in said second plane, a first switch operable by said feeler upon movement thereof in the first plane perpendicular to said draw tape, and a second switch operable by said feeler in the second plane parallel to said draw tape, each of said switches being effective to stop operation of said motor in a given direction of rotation.
 2. Arrangement according to claim 1 wherein the feeler is movable in one plane of movement by means of an element coupled with the bottom board.
 3. Arrangement according to claim 2 wherein the moving element is an adjustable release pin.
 4. Arrangment according to claim 1 wherein both switches and at least a part of said feeler are substantially located within the header but with the end portion of the feeler disposed exteriorly of the header.
 5. An arrangement as claimed in claim 4 wherein the exteriorly disposed feeler end portion is offset from the body thereof and disposed in the path of vertical movement of the blind.
 6. Arrangement according to claim 1 wherein the feeler has a slotted passage opening which encloses the draw tape substantially on all sides.
 7. Arrangement according to at least claim 1 wherein the feeler and both switches are mounted on a base plate installed in the header. 